Interest-Only Loans: What Is an Interest-Only Loan?
Starting With the Basics
If you have ever looked at two mortgage quotes and wondered why one monthly payment is so much lower than the other, an interest-only loan may be part of the answer. It is a way of borrowing where your monthly payment covers the interest on the loan, and nothing else. The amount you originally borrowed stays where it is until the end.
That single difference changes a great deal, so it is worth understanding properly before you decide anything.
Who Should Keep Reading
This guide is for UK homeowners, first-time buyers comparing mortgage types, landlords considering buy-to-let, and anyone approaching the end of an existing interest-only term. It will also help if you simply want to understand what your lender means when they ask about your "repayment strategy".
What an Interest-Only Loan Actually Is
An interest-only mortgage is a loan where each monthly payment covers only the interest being charged. None of it reduces the capital, which is the sum you borrowed in the first place. So if you borrow £200,000 over 25 years on an interest-only basis and make every payment on time, you will still owe £200,000 at the end of the 25 years.
UK banks, lenders and consumer bodies all describe it the same way, which is helpful because it removes any ambiguity. The monthly cost is lower than a repayment mortgage; the debt itself is not. The full balance becomes due at the end of the term, usually as a lump sum or through a separate arrangement you have set up alongside the mortgage.
Lower monthly payments do not mean lower debt. They mean the debt is waiting for you at the end.
Interest-only borrowing is available on both residential and buy-to-let mortgages in the UK, though the criteria and expectations can differ significantly between the two.
How It Works in Practice
When you apply, a lender will assess affordability as usual, but they will also want to know how you intend to clear the capital at the end of the term. This is often called an exit strategy or repayment vehicle, and lenders expect it to be credible from day one rather than something you will figure out later.
Common routes include selling the property, drawing on savings or investments such as ISAs, using a pension lump sum, receiving proceeds from another asset, or remortgaging. For buy-to-let landlords, the plan is frequently the eventual sale of the property, with rental income covering the interest in the meantime.
Eligibility tends to be tighter than for repayment mortgages. Many lenders require a lower loan-to-value ratio, meaning you need meaningful equity or a larger deposit. Some set minimum income levels or minimum equity thresholds. It is not unusual for interest-only deals to sit with specialist or private lenders rather than the high street mainstream, particularly for larger loans or unusual circumstances.
Why People Choose This Route
The main attraction is monthly cash flow. Because you are not repaying capital, the monthly payment can be substantially lower, which frees up income for other commitments, school fees, business costs or investment.
For landlords, interest-only is close to standard practice. It keeps monthly outgoings low relative to rental income, improves yield on a cash-flow basis, and fits a strategy where the property will eventually be sold or refinanced. Residential borrowers with irregular or bonus-heavy income sometimes prefer it too, planning to reduce the balance through lump sums rather than fixed monthly repayments.
These loans are far from a historical curiosity. The Financial Conduct Authority has reported that interest-only mortgages made up around 9% of all regulated UK mortgages, so this is a live part of the market, not a legacy product. That said, the FCA has also focused closely on repayment risk and whether borrowers genuinely understand the obligation they are taking on. Both things are true at once: it is mainstream, and it needs care.
Weighing the Benefits Against the Risks
| Pros | Cons |
|---|---|
| Noticeably lower monthly payments than a repayment mortgage | The capital balance never reduces through monthly payments |
| Frees up monthly cash flow for other goals or commitments | Total interest paid over the term is usually higher |
| Well suited to buy-to-let, where rent covers interest | A large lump sum falls due at the end of the term |
| Flexibility to make lump-sum overpayments when funds allow | Repayment plans based on investments or house prices can underperform |
| Can support borrowers with irregular or bonus-based income | Tighter eligibility: lower LTV, higher income or equity requirements |
| Available on residential and buy-to-let bases | You may be forced to sell or remortgage if the plan falls short |
Points Worth Pausing On
The end of the term is the moment that matters. If the balance has not been cleared, you will need to repay it, remortgage, or sell the property. Remortgaging at that stage is not guaranteed, particularly if you are older, your income has changed, or lending criteria have tightened since you first borrowed.
Be honest about your repayment plan. If it depends on investment growth, that growth may not arrive. If it depends on rising house prices, prices can fall or stall. If it depends on downsizing, consider whether suitable smaller homes will be affordable in your area and whether you would genuinely want to move.
Also factor in the higher lifetime interest cost. Because interest is charged on the full balance throughout, you typically pay more in total than on an equivalent repayment mortgage. And if you are on a variable or tracker rate, a rate rise hits your payment immediately with no shrinking balance to soften it.
Finally, review the plan regularly rather than once. Circumstances change, and a five-yearly check keeps small gaps from becoming large ones.
Other Routes You Could Consider
- Standard repayment mortgage - each payment covers interest plus capital, so the debt reduces steadily and is cleared by the end of the term. Higher monthly cost, far lower long-term risk.
- Part-and-part mortgage - a blend, where part of the loan is interest-only and part is on a repayment basis. Lower payments than full repayment, smaller lump sum at the end.
- Extending the mortgage term - stretching a repayment mortgage over more years reduces monthly payments while still clearing the debt, though it increases total interest.
- Offset mortgage - links savings to your mortgage to reduce interest charged, offering flexibility without leaving the capital untouched.
- Retirement interest-only (RIO) mortgage - designed for older borrowers, with interest paid monthly and the capital typically repaid when the home is sold or on death.
- Equity release or lifetime mortgage - for later-life borrowers who want to unlock property value without monthly payments, with its own significant trade-offs.
- Downsizing sooner - moving to a lower-value property now can reduce or remove the need for higher-risk borrowing altogether.
Common Questions Answered
Will my monthly payments really be lower? Usually, yes. Because you are only paying interest, the monthly figure can be considerably lower than a repayment mortgage on the same loan. The trade-off is that the full balance still needs repaying at the end.
What happens if I cannot repay the balance at the end of the term? You will generally need to repay it, remortgage onto a new deal, or sell the property. Speak to your lender early - well before the term ends - as options are broader when there is time to plan.
Do lenders check my repayment plan? Yes. UK lenders will normally want evidence of a credible strategy at the outset and may review it during the term. "I'll sort it later" is not an acceptable plan.
Is interest-only only for landlords? No. It is very common in buy-to-let, but residential interest-only mortgages do exist. Approval standards for owner-occupiers tend to be stricter.
Can I overpay or switch to repayment later? Many lenders allow overpayments and some allow a switch to repayment or part-and-part, subject to affordability. Check your specific terms and any early repayment charges.
Is it harder to qualify for? Generally yes. Expect requirements around loan-to-value, equity, income and the strength of your repayment plan.
Where Kandoo Fits In
Kandoo is a UK finance broker, and our job is to help you understand your options clearly before you commit to anything. Interest-only borrowing suits some people well and others not at all, and the difference usually comes down to the detail of your circumstances. We can talk you through how different structures compare, what lenders are likely to ask for, and which route fits your plans - without pressure and without jargon.
Important Information
This article is general information only and is not personal financial or mortgage advice. Interest-only mortgages carry the risk that you may not be able to repay the capital at the end of the term. Your home may be repossessed if you do not keep up repayments on your mortgage. Lender criteria, rates and availability change. Always seek regulated advice suited to your own circumstances before deciding.
Buy now, pay monthly
Buy now, pay monthly